'Might is right' is wrong, Payne warns

Defence Minister Marise Payne has warned against countries in the region adopting a "might is right" approach to international relations.

In what could be a veiled swipe at China, Senator Payne insisted nations have a right to be free from coercion when they reasonably object to the behaviour of other nations.

Relations with China have soured in the past year, with Beijing especially cranky about Australia's foreign interference laws.

"When Australia disagrees with the actions of another nation, including partners and allies, we say so," Senator Payne told the Shangri-La Dialogue in Singapore, the largest annual gathering of defence ministers, military chiefs and senior security officials across the region.

She pointed to Australia's stance on the South China Sea, which encourages countries to resolve territorial claims based on international law, as well as the publicly expressed disappointment that the US had withdrawn from the Trans-Pacific Partnership trade pact.

Senator Payne made the case that it was important for the US to continue to play an active role in the region to ensure peace and security.

The speech acknowledged disruption to international relations can create instability but emphasised strategic competition must be bound by rules that shouldn't be casually discarded.

"Adopting a 'might-is-right' approach is contrary to the interests of all nations," she said.

Senator Payne pointed to the recent Australia-East Timor settlement of a long-running maritime boundary dispute using a United Nations conciliation process.

"It's an example of the rules-based order in action," she said.

After years of bitter wrangling, Australia and East Timor in March signed a historic treaty at the United Nations to resolve a maritime boundary dispute in March. The deal also carves up $56 billion in potential revenue from oil and gas reserves in the Timor Sea.

Senator Payne also warned of the growing terrorism threat in southeast Asia, highlighting the recent suicide bombings in Surabaya, Indonesia and insurgency in Marawi in the Philippines.

"Nobody wants to see (Islamic State) take root in our region after being denied territory and legitimacy in the Middle East," she said.

Senator Payne will participate in a female leaders panel at the dialogue.

Incoming chief of the defence force Angus Campbell is also in Singapore for the dialogue, along with the bosses of the foreign affairs and defence departments.